This invention relates to a suction control device for an endoscope, which exerts a suction force in a channel of an endoscope when a medical instrument is not used and which does not exert a suction force in the channel while the medical instrument is used.
Generally, an endoscope is provided with a channel or channels through which a medical instrument such as a forceps is inserted into a body cavity or through which liquid medicine, water and air are supplied to the body cavity or body fluids are removed from the body cavity. While no medical instrument is inserted in the channel, particularly during a suction process, the proximal end of the channel should be closed to avoid an air leak. The proximal end of the channel is usually provided with a rubber valve having a slit. The slit is closed to minimize an air leak through the proximal end of the channel.
As the medical instrument such as a forceps is repeatedly inserted into, and withdrawn from, the channel, the valve is gradually worn, and the slit beomes broader and gradually fails to close the proximal end of the channel, and air will leak through the slit to reduce the suction force exerted in the channel.